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Horrible, horrible, horrible. I cannot even fathom the G forces on the body from a static line after one reaches terminal velocity (I am pretty sure one is close to terminal velocity after 200 feet of free fall). A 5 or 6-foot fall on to a gym rope (semi dynamic) while setting was jarring enough for me.I wonder what percentage of climbers use dynamic rope for hauling versus static, especially for big wall stuff.

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"You have to decide to do a flag, where you can broke your vertebrae or a barn door depending of your pro" - the poster formerly known as Champ

I wonder what percentage of climbers use dynamic rope for hauling versus static, especially for big wall stuff.

Pretty close to zero. In hauling mode, you would have to reel in all the stretch before even moving the bags each time.There are a million ways to do it but as a party of three, the leader fixes the lead rope and the haul line. The second cleans the pitch as the third jugs the static haul line quickly to begin leading the next pitch with a tag line to bring up the gear cleaned from the last . Bouncing around on a free hanging full length rope while spinning is enough to make you blow the little food you get on that adventure. Sawing over an edge bouncing up and down is a real threat on the non overhanging stuff.Repeat 35 times and you top out on El Cap.

Through a dumb screw-up I took a 40 foot fall on to a 13 Bluewater II once. I guess it isn't completely static, but only 'low elongation' because I was totally fine. Some energy could also have been absorbed by it whipping through shrubs. I probably had a little over 100 feet out total, running down from a tree at the top of the cliff with a big loose loop. I was clipped in with my GriGri and fell from a route anchor to just above the ground.

I wonder what ropes people are using for haul lines and what the actual elongation #s are. For the 13mm BWII it is 3.8% at 300 lbf and 8.4% at 1000 lbf. Are haul lines even more static?

Bluewater Big Wall haul line 10mm is at 3.8% elongation as well. It feels significantly stiffer than a dynamic rope. I use it for self belay top rope occasionally. A 200 foot fall is a different issue obviously.Once, we used a 300' version of this thinking we could haul 2 pitches in one shot. Maybe on the overhanging stuff but the bag gets hung up on less than vertical sometimes. Live and learn.

Mark, 230 feet is about 50 feet short of the 'height' of the Brooklyn Bridge. So I did some Googling and came up with this paper - http://people.math.gatech.edu/~weiss/pub/v2II.pdfOne of its conclusion is "Consider a 54-kilogram person who jumped feet first off the Brooklyn Bridge into the water, a fall of 84.4 m (280 feet). The jumper would hit the water moving about 28 m/s .... ". Or about 63 mph which is about one half of the terminal velocity of a human. So I way underestimated how far one has to fall to reach terminal velocity. I looked that up too and it seems like a 600 foot free fall will result in the human body reaching 90% terminal velocity. Grim.

Falling onto a stretched out gym rope while setting routes suck in general; 30~50 feet of rope out, self belaying with a Gri-Gri. Much more jarring than a good catch from a belayer using a dynamic rope.

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"You have to decide to do a flag, where you can broke your vertebrae or a barn door depending of your pro" - the poster formerly known as Champ

It would need further analyses, but I suspect, assuming the Yosemite climber didn't hit anything on the way down, that he may have survived if the haul line was attached to his hip harness instead of the chest. I would guess that even a haul line like the one DGoguen mentioned would stretch at least 10 or 12 feet over 200 at high impact. I wonder what the max force would be decelerating over that distance. The hips can handle a lot more force than the chest. In my fall the fall factor was a lot less, but the impact wasn't bad at all.

« Last Edit: May 22, 2013, 01:22:44 PM by M_Sprague »

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"Do not go where the path may lead, go instead where there is not a path and leave a trail."

Mark, 230 feet is about 50 feet short of the 'height' of the Brooklyn Bridge. So I did some Googling and came up with this paper - http://people.math.gatech.edu/~weiss/pub/v2II.pdfOne of its conclusion is "Consider a 54-kilogram person who jumped feet first off the Brooklyn Bridge into the water, a fall of 84.4 m (280 feet). The jumper would hit the water moving about 28 m/s .... ". about 63 mph which is about one half of the terminal velocity of a human. So I way underestimated how far one has to fall to reach terminal velocity. I looked that up too and it seems like a 600 foot free fall will result in the human body reaching 90% terminal velocity. Grim.

Falling onto a stretched out gym rope while setting routes suck in general; 30~50 feet of rope out, self belaying with a Gri-Gri. Much more jarring than a good catch from a belayer using a dynamic rope.

It's kinematics. Fundamental equation is: Velocity final (squared) = Velocity initial (squared) + 2 (acceleration)(distance). In this tragedy, his initial velocity was 0. Acceleration due to gravity is either 32ft/secsec or 9.8m/secsec- take your pick. If he fell 230 ft, he was therefore going, about 86ft/sec or 58.6 mph.

Mark, 230 feet is about 50 feet short of the 'height' of the Brooklyn Bridge. So I did some Googling and came up with this paper - http://people.math.gatech.edu/~weiss/pub/v2II.pdfOne of its conclusion is "Consider a 54-kilogram person who jumped feet first off the Brooklyn Bridge into the water, a fall of 84.4 m (280 feet). The jumper would hit the water moving about 28 m/s .... ". about 63 mph which is about one half of the terminal velocity of a human. So I way underestimated how far one has to fall to reach terminal velocity. I looked that up too and it seems like a 600 foot free fall will result in the human body reaching 90% terminal velocity. Grim.

Falling onto a stretched out gym rope while setting routes suck in general; 30~50 feet of rope out, self belaying with a Gri-Gri. Much more jarring than a good catch from a belayer using a dynamic rope.

It's kinematics. Fundamental equation is: Velocity final (squared) = Velocity initial (squared) + 2 (acceleration)(distance). In this tragedy, his initial velocity was 0. Acceleration due to gravity is either 32ft/secsec or 9.8m/secsec- take your pick. If he fell 230 ft, he was therefore going, about 86ft/sec or 58.6 mph.

Overly simplistic although typical Physics 101 answer. Ignores (air) resistence which is related to surface area and weight. At 230 feet this will be a significant factor - remember the feather, the cannonball and the vaccum. Thus the whole concept of TERMINAL velocity. Which varies with elevation (atmospheric density).